JPH0360447A - Dried composition with particle size distribution - Google Patents

Abstract

Fireproofing compositions comprise a hydratable cementitious binder and shredded polystyrene aggregate characterised in that the shredded polystyrene has a particle size distribution such that a range of about 0 to about 20 percent by weight of the particles is retained by a sieve having a hole size of 1.679mm and a maximum of about 40 percent by weight of the particles passes through a sieve having a hole size of 0.594mm and is retained by a sieve having a hole size of 0.0432mm. On addition of water, the compositions form settable, sprayable slurries which are capable of spray application to steel structural members and adhere to the member in the slurried state and after setting to provide fire and heat protection.

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION In summary, a fire resistant composition is provided. The composition includes a hydratable cementitious binder and a polystyrene aggregate that falls within certain particle size distribution limits. The composition can also include an air entraining agent and a fibrous material. Upon addition of water, the composition forms a coagulating sprayable slurry and is pumped to the point of application. The slurry can be spray applied to a steel structural member and will stick to the member in the slurry state and after solidification. Excellent flame and thermal protection is provided to the component regardless of the organic nature of the polystyrene aggregate.

During the construction of steel structures, thick coatings of inorganic materials are commonly applied to metal structural elements to achieve a number of purposes, including fire resistance, improved appearance and sound insulation. Although several types of formulations have been applied for these purposes over the years using a variety of techniques, successful systems have essentially It involves spraying the steel surface with a coagulating aqueous mixture containing an inorganic aggregate material, a mixture of fibrous materials such as humid bulking cellulose fibers and glass fibers, and an air entraining agent. This type of composition is
U.S. Pat. No. 3.719.573 and U.S. Pat. No. 3.8, with the most preferred application technique, namely pumping the aqueous mixture and spraying it directly onto the steel in one layer.
39.059 by Bragg.

To be suitable for such use, a coating mixture in both wet and dry conditions must possess a number of important properties. They must be able to hold very large amounts of water, allowing them to be pumped easily and to great heights. However, they must retain sufficient stiffness to prevent separation or precipitation of components and to allow adequate "yield" or coverage of the steel surface at a given thickness. Furthermore, the coating mixture must obviously adhere to the steel surface both in the slurry state and in the dry state. Also, the mixture must solidify without undue expansion or contraction resulting in the formation of cracks that significantly reduce the insulation value of the dry coating.

As mentioned above, this complex balance of properties has hitherto been substantially achieved with gypsum-vermicelli containing cellulose fibers. However, vermiculite is a naturally occurring mineral and is subject to variations in quality, hardness and uniformity. Furthermore, because vermiculite minerals must be foamed at very high temperatures before use, their cost is subject to unpredictable fluctuations in energy costs.

An alternative to gypsum-vermicelli mixtures is disclosed in commonly assigned US Pat. No. 4.751.024. Specifically, sprayable cementitious compositions containing shredded polystyrene as the lightweight aggregate are taught as refractory compositions for structural steel components. The present invention is directed to improvements in the i-acids disclosed in U.S. Pat. No. 4,751,024.

SUMMARY OF THE INVENTION In accordance with this invention, a sprayable cementitious composition comprising shredded polystyrene with specific particle size distribution limitations as a lightweight aggregate is produced and used as a spray-applied refractory composition for structural steel components. found to be used. Composition-like consistency and quality defined by pump effect, suspension effect and yield are achieved by controlling the size distribution of the shredded expanded polystyrene in the product. That is, it has been found that the degree of "shredability" of the expanded polystyrene affects the water ratio, apparent density, pumping efficiency and yield of the cement composition. The tacky composition provides excellent flame and thermal insulation protection to steel despite the organic nature of the polystyrene aggregate. Under flame test conditions, polystyrene aggregate shrinks, melts,
And indeed, it exhibits advantageous performance in that it disappears from the refractory composition matrix, leaving behind a uniform distribution of cavities that convey a very low effective thermal conductivity to the matrix. This in turn increases the effectiveness of the matrix as a barrier to heat transfer.

A number of manufacturing parameters must be controlled to obtain shredded expanded polystyrene within the particle size distribution limits of the present invention. A particle size distribution containing too many fine or coarsely chopped expanded polystyrene particles reduces the desired properties of the composition. The important parameters are the degree of melting in the expanded polystyrene plates used as starting material for the aggregate, the rate at which the plates are sent to the shredder, the shredding rotor speed, the roughness of the brushes in the shredder, and the and the allowable amount between.

Higher than optimal rotor speeds and/or lower than optimal feed rates produce shredded expanded polystyrene products that are too fine. In contrast, lower than optimal rotor speeds and/or higher than optimal feed rates produce coarse product. Poor quality expanded polystyrene boards, ie, boards with low melting rates, produce a coarse "beaded" shredded expanded polystyrene product that detracts from the benefits of the present invention.

Accordingly, the present invention provides a settable, sprayable, refractory composition capable of adhering to steel structural members in the slurry and solidified state, comprising a specific particle size distribution of a hydratable cementitious binder and a polystyrene aggregate. Directed. In a preferred embodiment, the composition also includes an air entraining agent and a fiber component.

The invention is further directed to refractory steel structural members coated with the refractory compositions of this invention.

DETAILED DESCRIPTION OF THE INVENTION The aggregate used in the present composition is shredded polystyrene particles, shredded loose expanded polystyrene beads, shredded loose expanded polystyrene bean nuts (backing insulation); Produced by shredding molded polystyrene beadboard or shredding extruded polystyrene. A method and apparatus for shredding expanded polystyrene is disclosed in U.S. Pat. No. 3,627.
No. 211 and No. 3.686.068,
The disclosure thereof is expressly incorporated herein by reference. As disclosed in these patents, the chopped particles have an irregularly shaped exterior surface, hundreds of cracks, and irregular edges. The shredding process opens a substantial number of cells at the surface of the foam bead, thereby allowing the cement binder to penetrate into the cellular structure and providing a more integral mixing between the binder and the particles.

A shredder particularly suitable for the present invention will be described with reference to FIG. The shredder box 40 has a support plate 42
A chamber 75 is shown defining a chamber 75 containing the . A round wire brush is mounted on the shaft and fastened to the shaft with adhesive. The assembly is mounted on a lathe and the outer diameter is polished to a -like diameter. That is, the excess length of the bristles is cut off and a light cut is made in all the bristles. The depth of the cut in this trim is approximately 0.020 inch.

This grinding causes a "set" in the bristles.

Rotor brush 48 is then attached to shaft 50 in box 40. Measurements are taken to establish the distance of the rotor arc from the bottom and back wall of the box 40. Stator brush 45.46 uses surface grinder 1. It is then molded to suit this arc by creep grinding. rotor brush 48 is removed from box 40;
Stator brushes 45,46 are attached to support plate 42 by suitable means, such as adhesive and/or lag screws, and rotor brushes 48 are again attached to shaft 5.
Attached to 0.

The rotor brush 48 is the stator brush 45.46
strategically positioned and chopped to give the desired particle size distribution of the material. Rotor and stator
The tolerance between the brushes is determined by any suitable means, such as by measuring the torque required to rotate the rotor brushes 48. Specifically, the shaft 50
A motor (not shown) is started to drive the
The current draw in the motor is then measured.

If there is significant contact between the rotor and stator brushes, the current will be high. In such case, the rotor brush 48 is removed and the stator brush bristles are trimmed with a hand belt grinder. The procedure is repeated until the desired tolerance between rotor brush 48 and stator brush 45,46 is obtained. Preferably there is little or no contact between the rotor and stator brushes.

Once the current is at the proper level, i.e. with little or no load, the expanded polystyrene is fed through a feed roll (not shown) at an established rate and the current is drawn by the motor. The draw is observed again. If the current exceeds the established level, the shiko redder is stopped and the "coagulation" in the rotor brush bristles is reduced. This is done by slowly manually rotating the rotor brush 48 in the direction of rotational motion. This is accomplished by rubbing the bristles with your hands. This procedure is carried out over the entire length of the rotor.

The shredder is certified by three separate expanded polystyrene runs. The shredded expanded polystyrene from each run is sampled and the particle size distribution determined as discussed below. If the measurements meet established particle size distribution requirements, the shredder is certified.

If the measurements do not meet the particle size distribution criteria, the "coagulation" of rotor brush 48 is readjusted.

Additional wire brushes are shown provided at 55 and attached to top plate 56 by lag screws. The bristles of brush 55 are extended downwards so that they are in close proximity to rotor brush 48 . Its function is to prevent chunks of expanded polystyrene from reaching the discharge opening 62 before being properly shredded. A suction means 60, such as a hood, is provided in communication with the chamber 75 through an opening 62 in the top plate 56. A suction means 60 is connected to the suction side of a material processing centrifugal fan (not shown) and collects the particles shredded by the aforementioned wire brush. The deflection plates 65 and 67 are connected to the suction means 60
helps direct the shredded particles towards the Deflection plate 67
It also serves to prevent the shredded particles from interfering with the raw material being sent through the feed opening lower 0 to the shredder box 40.

A suitable particle size distribution for shredded expanded polystyrene according to the present invention is determined by the amount of particles retained on a #12 standard sieve (with 0,0661 inch holes) and passing through a #30 sieve and passing through a #325 sieve. is expressed by the amount of particles retained at #16 Sieve is also #
12 and #30 sieves are used. Suitable amounts of particles retained on the #12 sieve, expressed as a weight percent, are from about 0 to about 20%, preferably from about 0 to about 10%, and amounts less than about 8% are particularly preferred.

A suitable amount of particles passed through a #30 sieve (with 0,0234 inch holes) and retained in a #325 sieve (with 0,001 inch holes) is less than about 40% by weight, preferably , less than about 30% by weight, with about 14-20% being particularly preferred. The desired amount of particles retained in the #12Jp sieve is due in part to the #30
Depends on the amount of particles that pass through the sieve and are retained by the #325 sieve. #30 when the amount of particles retained by the #L2 sieve is less than about 8% by weight
Preferably, the amount of particles that pass through the sieve and are retained by the #325 sieve is less than about 30% by weight.

Table 1 shows the effect of shredded expanded polystyrene particle size distribution on fire resistance performance.

In batch numbers i to 3, (passed through #30 sieve,
and the quantity of fine particles (as expressed by the weight percent retained on the #325 sieve) is kept in the same general grade dimension, while the quantity of coarse particles (as expressed by the weight percent retained on the #12 sieve) The number of particles was increased. Batch King showed the best overall performance with the highest R value and yield. Batch numbers 2 and 3, with approximately 3-fold and 4-fold increases in coarse particles, showed a decrease in R-value and yield, respectively.

In batch 4, the amount of fine particles was increased and was substantially outside the scope of the invention, while the amount of coarse particles was
The quantity of batch number l was approximated. The resulting composition retained little water (R value of 1.0) and exhibited low yields.

Non-use of water in attempts to increase yield makes the material unpumpable.

Referring now to FIG. 4, an example particle size distribution curve for a 20 g sample is shown. The weight percentages shown are
Based on a 20 g sample and about 16 grams of antistatic solution (resulting in about 4 grams solids) added for the purposes described below. The weight percent retained in #12 barrier was 1.5%. #30 Pass through the barrier,
And the weight percent retained in the #325 barrier was 33.4%. The performance of a composition with such a particle size distribution of shredded expanded polystyrene is
It was good.

As previously mentioned, a number of parameters must be controlled to obtain the particle size distribution of shredded expanded polystyrene according to the present invention. The degree of melting of the expanded polystyrene plate affects shredding and the particle size distribution of the shredded particles. If the beads used to form the board are fused too weakly, the shredding action will not tear the expanded polystyrene apart, but instead will only separate the beads from each other. This produces a coarse "bead-like" product outside the particle size distribution considered in this invention.

The rate at which expanded polystyrene sheets are sent to the shredder,
Plate volume (i.e., thickness) and rotor brush diameter also influence the particle size distribution of the resulting shredded expanded polystyrene. A feed rate that is too fast will result in a product that is too coarse, whereas a feed rate that is too slow will result in a product that is too fine. Plate feed rates in the range of about 140 cubic inches and rotor brush speeds of about 440 Orpm have been found to produce particle size distributions within the scope of the present invention.

Also influencing the particle size distribution of the shredded expanded polystyrene plate is the tolerance between the starter brush and the rotating brush and the relative speed of the brushes. If too large a gap exists between the starter and the rotating brush, or if the rotor brush rotates at too low a speed, a product that is too coarse will result. In contrast, if too small a gap exists between the brushes, or if the rotor brushes rotate at too high a speed, too fine a product will result.

Referring to Figure 2, a stirrer cap assembly is shown forming part of an apparatus used to measure the particle size distribution of a given sample of lightweight foamed polymer.

Assembly is inverted 8 #N a1geneil
Dou no Nyo<F? It includes a conical part 5. Funnel is coupling 15
is connected to the funnel through a tube 6, such as a 3/4'' PVC pipe. Gas, such as air, is transferred from the gas supply means to the quick-desorption mechanism 14 and l
/8'' NPT (standard pipe thread) T-fitting 16 and through the tube 6 to create a downstream draft in the chamber means. and a female pipe fitting for connection to a gas supply line (not shown).

Mechanism 14 allows easy and quick connection/disconnection between the agitator cap assembly and the air supply without the use of tools and without turning off gas pressure. The assembly also accommodates the sample, such as gas generated from a flexible gas drive tube 7 that is moved randomly in the conical section 5 to create a turbulent flow of gas that prevents the sample from clogging the screen 8 barrier. including means for stirring. Tube 7, preferably formed from latex rubber, is positioned approximately 3 inches above the shield wall to optimize sample agitation. A weight 4 of approximately 66 grams is attached to tube 7 to achieve good agitation.

The downward draft forces the particles released by the stirring tube 7 through the screen wall of the sieve 8. The gas supply for the downward draft is drawn from the main supply via a bypass loop 9 (in communication with tube 7) which is also a latex tube. This loop has a specially designed 1/32 inch inner diameter.
A means for automatically adjusting the exact gas pressure and flow rate through the bypass loop, such as an 8 inch closed nipple 10, is incorporated. Nipples can be cleaned by thoroughly cleaning and degreasing the nipples in a solvent such as acetone.
Made from 1/8" to 3/4" NPT closed nipples. The nipple is then filled with epoxy resin. When solidified, a 3/32 inch diameter hole is drilled in the center of the epoxy and carefully cleaned to remove loose particles without enlarging the hole. Nipple lO is connected to bypass loop 9 via coupling means 11 and connector means 12. Similar connector means 13 connect loop 9 to tube 6.

Gas pressure, flow rate and duration are important factors that must be controlled for optimal functioning of the device. The gas supply pressure and flow rate provide sufficient downward draft for suitable particles to pass through the filtration or size separation means, such as a sieve, and also prevent sample clogging of the filtration or size separation means. In order to cause the filtration or size separation means to move randomly and to create sufficient turbulence in the conical section 5, sufficient pressure must be set in the tube 7. Approximately 5O-51psi
Air pressure of approx. 4.9 5. A flow rate of Ocfm is preferred for a 20 gram sample of shredded expanded polystyrene. Each sieve has a duration of at least about 4 minutes.
It is preferred to provide an accurate and reproducible representation of the particle size distribution of a 20g sample. A 20g sample was found to represent 3601b, billet.

FIG. 4 shows the various elements used in conjunction with the agitator cap assembly to achieve the correct parameters. Any suitable known type of valve 31 is shown for rapid initiation or termination of pressure to the system.

A filter 32 is downstream of valve 31 and removes contaminants such as oil that leak from a gas source such as an air compressor (not shown). Such contaminants have deleterious effects on other elements in the system as well as separation results. Filter 2 also assists in removing condensed moisture from the system. Too much moisture in the filter 32
An air dryer (not shown) is used if present for processing.

A solenoid valve and timer 33 serve to automate the duration of a particular run. Pressure regulator 34 regulates the gas supply pressure to the desired level and includes a pressure gauge capable of withstanding the desired operating pressure.

A stainless steel two dollar valve 35 for varying the gas flow rate is incorporated into the flow meter 36. Flow meter 36 is connected to the line by 1/4 inch NPT fittings as an inlet and an outlet. A 1/4 inch nylon coiled hose 38 is connected to the agitator cap 39 and allows free movement of the agitator cap 39.

A preferred procedure for determining the particle size distribution of a given sample is as follows. The agitator cap assembly has a pressure of 50-51 psi and a pressure of 4.9-5. Osc
set at a flow rate of f m (moisture free)
Connected to air supply means.

As shown in Figure 2a, the assembly is tarred #
12 placed in communication with the sieve. #12 Under the sieve,
A blank (sieve with barrier removed) is placed to accommodate the volume of sample used. A tarred #16 sieve is placed below the blank and replaced with a second
Blank, tarred #30 sieve, and tarred #30 sieve
325 sieve rules. Blanks are generally not needed between the #30 and #325 sieves because the sample volume is sufficiently reduced by retention in the previous barrier. The entire sieve bag is then placed in a vessel to allow air flow and a suitable receptacle to accommodate the particles passing through the last sieve. FIG. 3 shows a top view of the receptacle with an opening 20 through which air and particles pass. The assembly is located in part of the surface 22 but does not cover the hole 24. Hole 24 allows air passing from the assembly to the receiver to escape.

A suitable sample is weighed. 80% Globanol and 20%
A suitable antistatic agent, such as a silicone/glycol solution, is added to the sample to reduce static electricity in the lightweight foamed polymer that builds up as a result of constant agitation of the polymer. The solution can be used without causing harmful particle deformation.
It is believed to form a thin layer on the particles. The stirrer cap is removed from the sieve bag, inverted and the conical section 5 is filled with sample. Then #1
2 sieves are removed from the sieve bag and placed over the wide mouth of the conical part 5 of the stirrer cap to act as a cover. Cone section 5, sample and #12 sieve are placed back into the sieve bag. Air supply is 5 (1
-51 psi pressure and 4.9-5. A flow rate of Os c fm is started and maintained for at least about 4 minutes.

The air supply is then discontinued, the conical section 5 is removed and the weight of the sample retained on the #12 sieve is then determined. The procedure is #1 as shown in Figure 2b.
6 sieves #30 and #3 as shown in Figure 2c
Repeat for 25 sieves. Measuring interest is #3
Due to the amount of sample passing through the #325 sieve and being retained on the #325 sieve, the procedure does not need to be applied directly to the #325 sieve. The amount of sample passing through the #325 sieve is ignored for this purpose.

The amount of material retained on the #16 sieve is not critical.

It is known to shred foam particles and mix the shredded particles with a granular slurry, where the granular material includes cement particles, sand, gypsum particles, etc. For example, as disclosed in U.S. Pat. No. 3.630.820 and U.S. Pat. It is reduced to prevent it from rising.

In the pumpable compositions of this invention, reduced buoyancy of the particles has been found to be essential for satisfactory transport of the composition through the pump mechanism and delivery line to the point of application. . In contrast, unshredded beads segregate within the slurry and the resulting localized concentration of beads clogs pumps, feed lines, and spray nozzles.

Shredded polystyrene particles are preferably used at a weight concentration of about 1% to about 5%, based on the total weight of the composition, prior to addition of water.

(Unless otherwise specified, all weight percentages given are based on the same.) These concentrations are designed to provide a pumpable, non-stick coating that exhibits the desired level of adhesion to steel materials and provides excellent flame protection. Preferred for providing a non-separating, -like slurry.

Additionally, the density of the slurry composition containing shredded polystyrene residue within the weight range is sufficiently low after application to ensure that the coating remains in place before and after solidification. Thus, "dropping" of the applied composition due to inadequate adhesion or mechanical and structural disturbances is minimized or eliminated.

The density of the shredded polystyrene preferably ranges from about 0.2 to 0.6 pounds per cubic foot, and more preferably from about 0.3 to 0.5 pcf. Preferably the particle size in the largest dimension is 174
smaller than an inch. Portland cement is used as the cement binder in the invention. However, it is generally preferred to use gypsum binders due to their convenient fire resistance properties. Gypsum, in relatively low amounts, e.g.
Although 60% by weight is used, it is generally preferred to use at least 75% by weight, based on the total weight of the composition, and more preferably at least about 8% by weight.
It is 5% by weight.

The fiber component in preferred compositions is either organic or inorganic. Preferably, the fiber component is a high-humidity bulking organic fiber, preferably as described in U.S. Pat. No. 3,719.
513 and 3.839.059, and inorganic fibers providing reinforcement, preferably glass fibers. The total amount of fiber component in the composition preferably ranges from about 4 to 20% by weight. Particularly preferred compositions include about 4 to 10% by weight high humidity bulking cellulose fibers and about 0 to 21% by weight. Amount %, most preferably from 0.1 to 21! Contains U% glass fiber. These particularly preferred fiber loadings, combined with a preferred loading of about 1-5% by weight of shredded polystyrene particles, allow for easy pumping without separation and placement in high yields, i.e., for a given thickness of application. The composition is optimized for deployment over a relatively large area per weight of dry composition. Yield is generally calculated as board feet per dry weight of the composition by methods known in the art. A particularly preferred composition is a dry composition of 45%
A high yield of at least about 20 plate feet per pound weight can be provided. Generally, yields range from about 25 to 35 board feet per 45 pounds dry weight.
be acquired.

Blowing agents or air entraining agents used in the compositions of the invention are well known in the art. Well known materials such as sodium alpha olefin sulfonates, sulfonic acid monoglycerides, sodium alkyl aryl sulfonates, and sodium lauryl sulfates are used to provide slurries of desired density and pumping effectiveness. used in appropriate amounts. a dry blowing agent is incorporated into the dry composition prior to addition of water;
Meanwhile, dry and liquid agents are added to the slurry composition. A preferred amount of air entraining agent is about 0.1-0.511% by weight. The combination of air entrainment and polystyrene shredding is used to provide homogeneity to the slurry, i.e. to prevent segregation of the aggregates for the time period required for pumping, atomization and solidification of the slurry. Especially convenient.

In some cases, it may also be desirable to incorporate a water retention agent into the mixture that incorporates more water into the slurry, thereby increasing pumping effectiveness and yield while retaining approximately the same level of adhesion to the steel. . A preferred water retention agent is hydroxypropyl methylcellulose.

The dried mass of this invention is converted into a pumpable slurry by the force of water. Generally, water is added to the dry mixture at the point of operation immediately before being pumped to the point of application. A water:cement binder ratio of about 1.0-1 to 2.5:1 is generally used to provide a pumpable mixture of desired consistency and viscosity. A preferred ratio is about 1.2-2.0:l. Generally, the range of slurry densities used that provides easy pumping is approximately 35 pc.
f-55 pcf.

[Brief explanation of drawings]

FIG. 1 is a side view of a shredder box for shredding expanded polystyrene into a size distribution according to the present invention. FIG. 2 is a front view of a stirrer cap used in determining the particle size distribution of a sample. Figures 2a, 2b and 2c are schematic diagrams of the apparatus used in determining the particle size distribution of a sample. FIG. 3 is a top view of the portion of the apparatus used in determining the particle size distribution of the sample. FIG. 4 is a schematic diagram of the gas supply line used in conjunction with the apparatus for determining the particle size fraction of the sample. 5th rM is a graph showing the size distribution of shredded expanded polystyrene according to the present invention. Fl(l l FIG, 3

Claims (1)

Claims: 1. A hydratable cement binder and particles ranging from about 0 to about 20 weight percent are retained by a standard #12 sieve, and up to about 40 weight percent particles are retained by a standard #12 sieve;
A dry composition comprising shredded polystyrene aggregate having a particle size distribution such that it passes through a #30 sieve and is retained by a standard #325 sieve. 2. The composition of claim 1, wherein the particle size distribution of the aggregate is such that less than about 8 weight percent of particles are retained by a standard #12 sieve. 3. The particle size distribution of the aggregate is such that less than about 30 weight percent of the particles pass through a standard #30 sieve and are retained by a standard #325 sieve. Composition. 4. The polystyrene aggregate is shredded expanded polystyrene beads, shredded polystyrene beadboard,
Claim 1 which is shredded polystyrene packing insulation or shredded extruded polystyrene.
, 2 or 3. 5. The composition of claim 4, wherein the polystyrene has a density in the range of about 0.2 to 0.6 pcf. 6. The composition of claim 4 comprising about 1-5% by weight of said polystyrene. 7. The composition according to claim 1, 2 or 3, further comprising a fiber component. 8. The composition according to claim 7, wherein the fiber component includes an organic fiber material and an inorganic fiber material. 9. The composition according to claim 7, wherein the fiber component comprises a high-humidity bulking organic fiber. 10. The composition according to claim 9, wherein the organic fiber is cellulose. 11. The composition according to claim 7, wherein the fiber component contains an inorganic fiber material. 12. The composition according to claim 11, wherein the inorganic fiber material contains glass fiber. 13. The composition of claim 6 comprising about 4-10% by weight high humidity bulking cellulose fibers and about 0-2% by weight glass fibers. 14. Claims 1 and 2 further comprising an air entraining agent
Or the composition according to item 3. 15. The composition according to claim 1, 2 or 3, further comprising a water retention agent. 16. The composition according to claim 15, wherein the water retention agent is hydroxypropylmethylcellulose. 17, a hydratable cement binder and a range of about 0 to about 20 weight percent particles are retained by a standard #12 sieve, and up to about 40 weight percent particles are retained by a standard #12 sieve.
1. A dry composition comprising shredded polystyrene aggregate having a particle size distribution such that the composition passes through a #30 sieve and is retained by a standard #325 sieve, an air entraining agent, and a fiber component; provides a coagulable slurry that can be sprayed onto a steel structural component and sticks to the component in the slurry state after the spray application, with the addition of water; and vinegar, forming a heat-protective adhesive coating. 18. A slurry formed by the addition of water to the composition of claim 1, 2, 3 or 17, wherein the slurry has a density in the range of 35 pcf to 55 pcf. 19. The slurry of claim 18, which provides a field yield of at least about 20 board feet per 45 pounds of the dry composition after spray application. 20. A fire-resistant steel structural member comprising a steel structural member coated with a slurry of the composition according to claim 1, 2, 3 or 17. 21. A fire-resistant steel structural member comprising a steel structural member coated with the slurry according to claim 19.